NAME

Perl::Critic::Policy::RegularExpressions::ProhibitRegexToStripAffix - Take a known prefix or suffix off a string without a regex capture.

VERSION

version 0.001

Perl::Critic::Policy::RegularExpressions::ProhibitRegexToStripAffix

A match that anchors a run of literal text to one end of the string and captures the rest is taking a prefix or a suffix off. substr does that without compiling a pattern, running it, and copying out a capture:

my ($name) = $file =~ m/\A(\w+)\.pm\z/;                       # reported

my $name = substr( $file, -3 ) eq '.pm' ? substr( $file, 0, -3 ) : undef;

my ($rest) = $line =~ m/\Aprefix-(.*)\z/;                     # reported

my $rest = index( $line, 'prefix-' ) == 0 ? substr( $line, 7 ) : undef;

PROHIBITED

m/\A(\w+)\.pm\z/              # a suffix, anchored at both ends
m/^(.*)\.tar\.gz$/            # $ and ^ as well as \A and \z
m/(.+)\.bak\z/                # .* or .+ reaches the start on its own
m/\Aprefix-(.*)\z/            # a prefix
m/\Afoo:(.*)/                 # a prefix, and .* reaches the end on its own
m/\A(\w+) \. pm\z/x           # whitespace under /x is not text

ALLOWED

m/(\w+)\.pm\z/                # unanchored: the last run of word characters
m/\A(\w+)\.(pm|pl)\z/         # alternation, and two captures
m/\A(\w+)\.pm\z/i             # /i: substr's comparison is case sensitive
m/^(.*)\.pm$/m                # /m: ^ and $ are line anchors
m/\A(\w+)\.pm\z/g             # /g
m/\A(\w+)[.]pm\z/             # a character class is not literal text
m/\A(\w+)$ext\z/              # interpolation
m/\A(\w+)\z/                  # nothing to strip
s/\.pm\z//                    # a substitution
qr/\A(\w+)\.pm\z/             # a compiled regex, which may be used elsewhere

CAVEATS

A capture of anything but .* or .+ also checks what it captures: m/\A(\w+)\.pm\z/ refuses foo-bar.pm, and substr takes the suffix off whatever is in front of it. When that check is the point, keep the regex and say ## no critic (ProhibitRegexToStripAffix) and why.

$ and \Z also match before a newline at the end of the string, and . does not match a newline without /s. substr knows nothing of lines, so for text that can end in a newline, chomp it first.

A modifier turned on by use re is not seen, only one written on the match. The scenarios in which you turn on global /img are quite rare, and you should simply not use this policy if your code does this.

METHODS

supported_parameters

default_severity

default_themes

applies_to

violates

BUGS

Please report any bugs or feature requests on the bugtracker website https://github.com/teodesian/perl-critic-policy-prohibitregextostripaffix/issues

When submitting a bug or request, please include a test-file or a patch to an existing test-file that illustrates the bug or desired feature.

AUTHORS

Current Maintainers:

• George S. Baugh <george@troglodyne.net>

COPYRIGHT AND LICENSE

Copyright (c) 2026 Troglodyne LLC

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.